Q: My St. Augustine has large round, dead patches in the grass. It's all happened in the past several weeks. What is it, and what can I use to stop it?

A: That's brown patch. It's a cool-season (primarily fall - October and November) disease that attacks the St. Augustine leaf blades where they attach to the runners. Pull on several of the blades, and they'll come loose easily, like a soggy facial tissue tearing in half. You will be able to see the decayed leaf tissue.

The disease is not fatal, but it does weaken the grass enough that other stresses of extreme cold or drought can finish it off. You'll want to control it, just to keep your lawn more attractive, anyway.

It is spread by moisture on the grass, so water only in early morning hours. Your local garden center will have several fungicides labeled for its control. The big national stores seem not to have turf fungicides in many cases. If you treat quickly enough, the browned areas will start to sprout new green blades this fall. The roots and runners remain unaffected.

Q: What can you tell me about the sterile lantana? I've been reading a lot about it online. How do I know I'm getting a sterile one? Does it really bloom better? Does it not produce berries?

A: The popular variety 'New Gold' is anything but new, having been in the nursery market 30 or more years. Like a mule, 'New Gold' is a triploid, rendering it sterile. Correct, it does bloom more consistently, and true, it does not produce fruit. It grows to 12 to 15 inches tall, and it's a rich golden yellow color. However, don't overlook all the other great lantana varieties, sizes and colors. Even though they may cycle in and out of flower occasionally, and even though some types may produce a certain number of fruit, they are some of our finest sources of summer color in the landscape.

Q: I need to have some pruning work done on my red oak tree. What time is best?

A: Winter is always a great time to prune shade and fruit trees that need some type of corrective help. Specifically in the case of oaks, it's an outstanding time, because the vectors that spread oak wilt fungus are inactive in the winter. Spring is taboo, as oak wilt fungal mats are active in infested trees, so that is the season of most active transmission. Pathologists tell us that midsummer, during the hottest weather, is another suitable time to prune. Fall should be safe, but honestly, I'd wait for winter. Hire a certified arborist with experience in oak wilt issues. That's especially critical if the disease is active in your area.

Q: Would it be possible to get grass to grow on top of an old concrete slab? We have six dogs. I'm not physically able to break the concrete, and I can't afford to hire a landscaper to do it. How much soil would I have to add?

A: That is probably not a good plan. You'd be better off giving the dogs some space immediately adjacent to the slab, and then to concentrate your efforts on getting the grass to grow there. You would need a foot of topsoil before you would be able to grow grass, and even then, drainage would be a concern with solid concrete below. Dogs will trample your grass, and you would be left with a foot or more of mud every time it rains. The dogs will be fine on the concrete, and it will be a lot easier to keep it (and them) clean. If you absolutely must have grass there, ask a scout troop or church group to help break up the concrete. Adults could break it, and the teens could cart it away.

Q: Is it unusual that my elephant ears are blooming for the third time this year? I'd like to dig the bulbs and protect them over winter so I won't lose them. How do I do that?

A: It's not unheard of for an elephant ear plant to flower several times (or almost ongoing) over a summer and fall. Elephant ear bulbs should be cold-hardy south of Interstate 20 most winters, and odds of their surviving are probably better in those areas if they're left where they are and mulched with several inches of shredded tree leaves. For anyone north of that approximate line, or for anyone who needs to dig and save them, let them become air-dry on newspaper in the garage for a few days, then pack them loosely in boxes of dry sawdust or perlite. Store them indoors at 60 to 65 degrees over winter.

Mail questions to Neil Sperry, c/o Features, San Antonio Express-News, P.O. Box 2171, San Antonio, TX 78297-2171, or email him at SAENgardenQA@sperrygardens.com. For more of his advice, go to his Facebook page